ELEMNT GPS computers use a GPS receiver, a barometric altimeter and an internal thermistor (primitive thermometer) among other sensors to calculate and record ride data. Since all sensors have limitations which can affect accuracy and consistency, familiarity with these limitations helps ensure the best accuracy on your ride.
Why an ELEMNT computer and the Wahoo app may record differing elevation numbers
The two record elevation in different ways, so their numbers can differ for the same ride.
Wahoo app: If you use a GPS-enabled workout profile, the app records your GPS track during the workout. Afterward, during post-processing, it looks up elevation from the base maps for the area where the track was recorded. The app does not show elevation or grade data while you're working out.
ELEMNT ACE, BOLT, and ROAM: These computers primarily calculate elevation with a barometric altimeter, which measures air pressure.
Why the barometric method is more accurate: GPS elevation is often unreliable because of satellite positioning and coverage. In our testing, we commonly found GPS elevation errors in the hundreds of meters. For consistent, accurate elevation data, GPS-adjusted barometric altimeter data works best.
GPS and Speed Data
Many ELEMNT and WAHOO features depend on good GPS data to track location, speed, and progress. Speed is calculated using GPS data by default, but a standalone speed sensor can be paired (for cycling type workout profiles in WAHOO app) which will override GPS data in regards to speed and generally improve accuracy - especially when GPS data is affected by the factors described below.
If you are having issues with the ELEMNT or WAHOO app recording your exact speed or location, please be aware that GPS requires a line of sight to the sky in multiple directions to receive straight-line signals from GPS satellites and can be hampered or obstructed by:
- Dense tree or cloud cover (especially in or near storms)
- Tall buildings
- Bridges and tunnels
- Land forms like mountains and cliffs, particularly when they are close to you.
- Electrical interference from solar flares or electronics like bike lights or cameras
- Or other large objects
Additional factors that can affect GPS data are described in Bicycling.com's article How Your GPS Lies to You.
Not all services calculate (and/or correct) GPS and elevation data equally, even with the same ride data. Displayed data may differ when analyzed by third party services.
Grade/Elevation Data
Since barometric altimeter accuracy is related to the physical size of the sensor and dependent on stable atmospheric pressures, hand-held altimeter accuracy is inherently limited and subject to changing weather patterns. Because of this, many third party apps like Training Peaks and Strava use GPS data to correct recorded elevation. Nonetheless, because of the inherent limitations in GPS technology for accounting for topography, altimeter-based elevation calculation remains the best solution. For the best elevation data, wait for your ELEMNT to acquire a strong GPS signal prior to starting a ride.
- Not all services calculate (and/or correct) GPS and elevation data equally, even with the same ride data. Displayed data may differ when analyzed by third party services.
- Pairing a speed sensor like the TRACKR Speed sensor to your ELEMNT will generally help to correct GPS inaccuracies and improve grade data.
For further discussion of elevation data discrepancies, see Why are there Elevation differences in my ride data?
Temperature Data
ELEMNT computers measure temperature using an internal thermistor, a semi-conductor resistor on the board which is sensitive to temperature, rather than a precision thermometer. Measurements are designed to be relatively accurate in normal riding conditions, but occasionally differ from true ambient temperatures when affected by the following factors:
- Sudden changes in ambient temperature take time to affect the sensor
- Prolonged exposure to direct sunlight can warm the device in excess of ambient temperature
- Charging (typically with an external battery) can cause additional warming
If you are experiencing unexpected negative or extremely high reported temperatures, this may indicate a hardware issue. In those cases, please submit a support request and our support team will be happy to assist.
Calorie Data
The ELEMNT and WAHOO app's calorie consumption calculations are different, depending on what sensors you have paired.
- With a power meter, the calorie consumption is directly correlated to your accumulated power output.
- Without a power meter, calorie consumption is estimated based on heart rate data if a heart rate monitor is paired, with an algorithm which accounts for biological sex, weight, and age.
For the most accurate analysis, use a power meter. If not available, use a heart rate monitor. For more information on those calorie consumption calculations, see Calorie consumption data calculation [Wahoo app + ELEMNT app].